The automotive industry has turned to the use of interior trim components such as door panels comprising a polyvinyl chloride shell. See, for example, the trim components disclosed in U.S. Pat. No. 3,123,403. The acceptance of such components has been primarily due to this type of construction accommodating a wide latitude in styling and color, and grain effects which are most desired, particularly in the interior design of automobiles.
The current state of the art includes a pre-formed grained vinyl shell made from dry thermoplastic powder particles which are applied to a heated shell mold from a powder box to form a continuous monochromatic one-piece shell.
In order to enhance the interior decor of an automobile, interior door panels and other parts have been prepared which include two separate plastic shell sections.
The use of multi-color plastic is also known in the manufacture of colored filaments. Such manufacture includes use of a compartmented spinning head for making two-colored yarn as disclosed in U.S. Pat. No. 3,049,397 issued Aug. 14, 1962 for Process of Making Space-Dyed Yarn.
U.S. Pat. No. 3,028,283 issued Apr. 3, 1962 discloses a golf grip of multi-color strips with a separating bead simulating a paint stripe.
Apparatus and method for multiple colored thermoplastic floor materials are set forth in U.S. Pat. No. 3,383,442 issued May 14, 1986.
U.S. Pat. No. 4,562,025 issued Dec. 31, 1985, with a common assignee to the present application, covers a Mold Method and Apparatus for Multi-Color Plastic Shells in which shell segments have their edges bonded at a common break-line.